code: def test_reduce_mean_equal(
      x: Union[List[List[int]], List[int]],
      y: List[int],
      mask: Optional[List[int]],
      expected_output: float,
  ):
      assert expected_output == layers_utils.reduce_mean_equal(
          x, y, mask
      )
  
file_path: rasa/tests/utils/tensorflow/test_layers_utils.py
imports: import pytest
  import tensorflow
  import numpy
  from typing import List, Optional, Union
  import rasa.utils.tensorflow.layers_utils
label_desc: Use image node_id 5 for calling a global function with example usage: test_reduce_mean_equal(x, y, mask, expected_output) without return types